Auto Update Script

I have a router that I want to update but not tell 3am. I have this scheduler script.

/system scheduler
add interval=1d name=system_update on-event=“/system package update\r
\ncheck-for-updates once\r
\n:delay 1s;\r
\n:if ( [get status] = "New version is available") do={ install }\r
\n” policy=ftp,reboot,read,write,policy,test,password,sniff,sensitive,romon start-date=jan/01/2000 start-time=03:00:00

After it updates I want the scheduler disabled. How would I have it disable itself but still run the update once?

To disable a scheduler

/system scheduler set disabled=yes [find name=system_update on-even]

name= put the name of the scheduler to disable.